Platinum catalysts are reported for the direct, low-temperature, oxidative conversion of methane to a methanol derivative at greater than 70 percent one-pass yield based on methane. The catalysts are platinum complexes derived from the bidiazine ligand family that are stable, active, and selective for the oxidation of a carbon-hydrogen bond of methane to produce methyl esters. Mechanistic studies show that platinum(II) is the most active oxidation state of platinum for reaction with methane, and are consistent with reaction proceeding through carbon-hydrogen bond activation of methane to generate a platinum-methyl intermediate that is oxidized to generate the methyl ester product.

Metabolic regulation has been recognized as a powerful principle guiding immune responses. Inflammatory macrophages undergo extensive metabolic rewiring1 marked by the production of substantial amounts of itaconate, which has recently been described as an immunoregulatory metabolite2. Itaconate and its membrane-permeable derivative dimethyl itaconate (DI) selectively inhibit a subset of cytokines2, including IL-6 and IL-12 but not TNF. The major effects of itaconate on cellular metabolism during macrophage activation have been attributed to the inhibition of succinate dehydrogenase2,3, yet this inhibition alone is not sufficient to account for the pronounced immunoregulatory effects observed in the case of DI. Furthermore, the regulatory pathway responsible for such selective effects of itaconate and DI on the inflammatory program has not been defined. Here we show that itaconate and DI induce electrophilic stress, react with glutathione and subsequently induce both Nrf2 (also known as NFE2L2)-dependent and -independent responses. We find that electrophilic stress can selectively regulate secondary, but not primary, transcriptional responses to toll-like receptor stimulation via inhibition of IκBζ protein induction. The regulation of IκBζ is independent of Nrf2, and we identify ATF3 as its key mediator. The inhibitory effect is conserved across species and cell types, and the in vivo administration of DI can ameliorate IL-17–IκBζ-driven skin pathology in a mouse model of psoriasis, highlighting the therapeutic potential of this regulatory pathway. Our results demonstrate that targeting the DI–IκBζ regulatory axis could be an important new strategy for the treatment of IL-17–IκBζ-mediated autoimmune diseases.

A constant stress fracture experiment of Oshima granite was carried out at the confining pressure of 40MPa. Hypocentres of 2064 acoustic emissions were located during the experiment. Using the 'correlation integral', we found that the spatial distribution of hypocentres of acoustic emission is a fractal, and that the fractal dimension decreases with the evolution of rock fracturing. The spatial distribution of earthquake's hypocentres reveals fractals ranging from regional to worldwide distribution. If we extrapolate from laboratory measurements, it is possible to predict the occurrence of large earthquakes by the decrease in the fractal dimension.

Abstract. This paper describes the localization of deformation acceleration in the period prior to dynamic failure in hornblende schist rock under triaxial compression using acoustic emission (AE) monitoring. Rather than stabilize the failure process by controlling axial stress to maintain a constant rate of AE (for monitoring AE hypocenters) as in previous works [e.g., Lockner et al., 1991 ], we have instead developed a rapid multichannel data collection system. This enables us to elucidate the dynamics of fault nucleation under condition of constant stress (creep) loading, which is a better approximation to low strain rate condition in the Earth and allows both quasi-static and dynamic crack growth to occur. The waveforms of more than 8000 AE events which occurred mainly during a 15 s period were recorded on 32 channels, with a sampling rate of 50 ns and mask time of 200 gs. Hypocentral locations of AE sources revealed that the fault initiated at one end of the core and then propagated into the unfaulted rock with a process zone (fault front) of intense cracking. We found that there were two different processes operating during the quasi-static nucleation of a shear fault, namely, a process zone in front of the fault tip and a "wake" of damage zone following the process zone. The process zone had the following features: (1) major tensile cracking, (2) low b value and fewer larger events, and (3) strong self-excitation. The mechanism of crack interaction and fault growth was, therefore, a mutual enhancement on dilatation due to tensile cracking. On the other hand, the damage zone was characterized by (!) major shear cracking, (2) low b value and more larger events, and (3) weak self-excitation, indicating that in the damage zone, following the development of a shear fault, linkage between cracks became the major mechanism of crack interaction and fault development. The mutual changes of b value and self-exciting strength observed in our experiments seem to occur as a result of the hierarchy of fault growth, which was not observed under slowed down loading conditions. Therefore our experimental results, under a realistic approximation of the dynamic condition of the Earth, are meaningful for the problems of earthquakes as well as rock bursts.

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